1. Field of the Invention
The present invention relates to a computer program product, system, and method for managing metadata for caching devices during shutdown and restart procedures.
2. Description of the Related Art
In distributed storage systems, one or more storage servers serve data to storage clients. The storage clients are equipped with local caches that use non-volatile memories to locally cache data for faster access. These memories are typically Flash, Phase Change Memory, etc. The storage server uses a coherency protocol to manage the coherence of the data at different clients, ensuring that each client will have the most up-to-date copy of data managed by the storage server for data maintained in the client local cache so that no stale data will be served to the user that accesses data through one of the clients.
In the event of a power cycle, the clients need to communicate with the storage server to discover what data should be purged. purge data that may be invalid.